Hi,
I'm making a tile-based game where there are several layers of tiles on map, so player can be covered by tiles from higher layer. I also render tiles to texture slightly bigger than the screen, which is updated only when view gets close to it's edge. In order to make this layer effect I make two textures, one for tiles below player and one for tiles above him. The problem is that the upper texture needs to be transparent in places where there's no tiles, so tiles from lower texture can be seen, but RenderTexture seems to be initially black and I can't see a way to make it transparent.
Any ideas?